Many coal-fired power plants today are struggling to remain viable, due to both competition from natural gas and increasingly stringent environmental restrictions on emissions, which require expensive retrofits and the development of new technologies to ensure compliance. In addition to rules already in place, on Jun. 2, 2014 the Environmental Protection Agency announced a proposal to reduce CO2 emissions from power plants to 30% below 2005 levels by 2030. Per a fact sheet released in January 2015, the EPA expects to issue final rules under the “Clean Power Plan” in the summer of 2015. These are likely to put increased pressure on coal generation, which is responsible for 75% of power-related CO2 emissions.
Owners of coal-fired power plants are currently limited to three options for responding to these economic and environmental pressures:                a. Switching to a less carbon-intensive fuel source, such as natural gas or biomass.        b. Installing emissions controls such as scrubbers.        c. Decommissioning and retiring the plant.        
The first two of these options, which keep the plant operational and available, are expensive, and are only warranted in cases where the plant will enjoy continued revenues sufficient to pay back the capital investment required. Large revenue streams are more likely when plants can act as baseloading facilities, producing power at all times (this is also the mode of operation favored by traditional Rankine cycle coal plants). However, low natural gas prices and the widening availability of off-peak wind generation put pressure on energy prices overnight, thereby squeezing baseloading coal plant's margins.
Consequently, many coal plants choose the third option from the list above, retiring rather than investing additional money into the facilities. According to the U.S. Energy Information Agency, upwards of 50,000 MW of coal-fired generation are being taken out of service between 2010 and 2020, before accounting for the Jun. 2, 2014 E.P.A. announcement. At the same time as off-peak prices are falling in response to increasing supply and lowering fuel costs, the need for on-peak generation continues to grow. The Energy Information Association (EIA) predicts 12,000 MW of simple-cycle (peaking) generation growth from 2011 to 2020. Removing more baseloading coal plants from operations will only increase this need.